/*
 * @Description: 
 * @Author: yeeChen
 * @Date: 2022-12-19 14:29:40
 * @LastEditTime: 2022-12-19 14:33:10
 * @LastEditors: yeeChen
 */

// 防止全局变量污染问题

const userName = ' 张三'

function sayHello() {
    console.log('大家好我是'+username);
}